This Section of the EIA Report presents the results of an assessment of the impact of construction and operation of the drainage system of the Project (Drainage Improvement in Tsuen Wan and Kwai Chung-Tsuen Wan Drainage Tunnel-Investigation), as part of the drainage improvement in Tsuen Wan Kwai Chung & Tsing Yi, on existing fisheries resources, fishing operations and fish culture activities based on the findings of the Water Quality Impact Assessment.
A desktop literature review was conducted in
order to establish the fisheries importance of the area surrounding the Outfall
O-1. Information from the water quality
assessment was used to determine the size of the Study Area as that potentially
affected by perturbations to water quality parameters. This area, including Ma
Wan Fish Culture Zone, became the Study Area for this fisheries impact
assessment (Figure 10.1). The importance of fishing resources and
fisheries operations identified within the Study Area was assessed using the EIAO-TM. The potential impacts due to
the construction and operation of the drainage tunnel have been assessed
(following the EIAO-TM Annex 17 guidelines) and the impacts
evaluated (based on the criteria in EIAO-TM
Annex 9).
The availability of literature on the fisheries resources of the Study Area comes mainly from the AFCD 1996-1997 (1) and 2001-2002 Port Survey (2). Other relevant reports from the Study Area have been reviewed.
In
The findings of fisheries surveys, fishermen’s interviews and accompanying literature reviews (5) conducted for AFCD’s Fisheries Resources and Fishing Operations in Hong Kong Waters Study have determined that commercial fish species reproduce throughout the year, though spawning for the majority of species appears to be concentrated during the period from June to September. The marine waters within the Study Area were not identified as a primary nursery ground for commercial fisheries (fish fry production density less than or equal to 50 tails per hectare with reference to the AFCD’s Port Survey 2001/2002).
In 2002, the estimated fisheries production
in
Based on the latest AFCD Port Survey data
(8), the
highest range of fisheries production (ie 600 – 1000
kg ha-1) was recorded near Cheung Chau,
Penny’s Bay, Kau Yi Chau,
Po Toi, Ninepin Group and Tap Mun. The top 10 families captured in
Up-to-date information from AFCD is available
for use in this EIA and can be collated to allow an assessment be made of the
importance of Fishing Zones in the Study Area to the
The Study Area interfaces with 5 Fishing Areas (including one Fish Culture Zone) as identified in the AFCD Port Survey Report (9) (Figure 10.1). These Fishing Areas are identified as follows:
·
Ma Wan
(Fish Culture Zone)
· Tsing Yi
· Tsuen Wan
· Ting Kau
· Shum Tseng
The area and number of vessels operating during 1996-1997 in each of the Fishing Zones is presented in Table 10.1.
Table 10.1 Area (ha) and Number of Vessels Operating During 1996 - 1997 in Each AFCD Fishing Zone within the Study Area
|
Code |
Fishery Area |
Area (Ha) |
Vessels < 15m |
Vessels > 15m |
All Vessels |
|
0025 |
Ma Wan |
418.82 |
253.9 |
0 |
253.9 |
|
0034 |
Tsing Yi |
1326.12 |
140.1 |
0 |
140.1 |
|
0035 |
Tsuen Wan |
169.38 |
116.9 |
0 |
116.9 |
|
0036 |
Ting Kau |
224.26 |
121.5 |
0 |
121.5 |
|
0037 |
Shum Tseng |
85.98 |
4.6 |
0 |
4.6 |
|
Total |
|
2,224.56 |
* |
* |
* |
|
Total of all Fishing Zones
in Hong Kong |
181,790.97 |
2,352.2 |
266.4 |
2,618.5 |
|
|
Percentage of Hong Kong
Total |
1.2 % |
* |
* |
* |
|
*No values can be calculated for these parameters from the information provided,
as it cannot be determined whether the vessels reported as operating within one
zone are the same vessels that are reported for another zone.
The total number of vessels varies widely from 4.6 in Shum Tseng Fishing Area to 253.9 in Ma Wan Fishing Area. According to the AFCD 1996/ 1997 Port Survey, the total fishing production in those fishing areas is from vessels not exceeding 15m (Table 10.1). No vessel exceeding 15m operated in the Fishing Areas (Table 10.1).
The number of vessels ranged from 100 to 400 in the Study Area. According to the AFCD 1997 Vessel Count, the most common type of vessel operating within the Study Area is sampan (P4/7) with particularly high numbers (285) recorded in Ma Wan, and (34) recorded in Tsuen Wan. Vessels such as long liner, gill netter, hand liner and miscellaneous craft were reported to operate within the Study Area with relatively low numbers (9) being reported in Ma Wan home port and approximately 31 being reported in Tsuen Wan home port. The information presented indicates that the fisheries production within the Study Area was mainly derived from P4/7 vessels, shrimp and hang trawlers.
The overall fisheries production (adult fish
and fish fry) ranged widely from approximately 14 kg ha-1 (Shum
Tseng) to >200 kg ha-1 (Tsuen Wan) (Table
10.2). These
values are not in the high range for production in
Table
10.2 Fisheries Production Values from each AFCD
Fishing Zone within the Study Area (1996 – 1997 Port Survey)
|
Code |
0025 |
0034 |
0035 |
0036 |
0037 |
|
Fishing
Areas |
Ma Wan |
Tsing Yi |
Tsuen Wan |
Tin Kau |
Shum
Tseng |
|
Total
Production |
|
||||
|
Adult Fish
(kg) |
81,988.08 |
47,425.64 |
35,200.56 |
36,041.55 |
1,251.06 |
|
Fry
(Tails) |
7,661.29 |
- |
- |
- |
- |
|
Value
(HKD) |
4,469,869.80 |
1,888,784.37 |
1,362,072.38 |
1,408,040.13 |
7,661.29 |
|
Production
(Ha-1) |
|
||||
|
Adult Fish
(kg) |
195.76 |
35.76 |
207.82 |
160.71 |
14.55 |
|
Fry
(Tails) |
18.29 |
- |
- |
- |
- |
|
Value
(HKD) |
10,672.14 |
1,424.29 |
1,424.29 |
6,278.59 |
89.11 |
|
Rank
Production (Ha-1) |
|||||
|
Adult Fish
(kg) |
48 |
139 |
47 |
63 |
157 |
|
Fry (Tails) |
68 |
- |
- |
- |
- |
Of the 5 fishing areas identified, three of
the fishing zones were ranked as recording high or medium value for adult fish
production (Ma Wan 48th, Tsuen Wan 47th
and Ting Kau 63rd out of the 179
zones). Ma Wan ranked 68th
for fish fry production. Tsing Yi and Shum Tseng recorded low ranked adult fish
production (Tsing Yi 139th and Shum Tseng
157th). With the exception of
Ma Wan, no fish fry capture operations was recorded in the fishing areas within
the Study Area.
According to the AFCD Port Survey data (10), the top five adult fish species caught in the sector Western Harbour (SE03) included the mixed fish species, Siganus canaliculatus (Rabbitfish), Acetes spp (Silver shrimp), Sebasticus marmoratus (Rockfish) and Argyrosomus spp (Croaker). The main fish species reported in catches from the Study Area are of low commercial value (<HK$10/kg) including mixed species (juveniles of trash fish species such as Caranx kalla, Siganus canaliculatus, Sardinella sp., Leiognathus brevirostris, Clupanodon punctatus) (Table 10.33). Silver shrimp, croaker, yellow croaker, sea bream and conger pike eel are regarded as of high commercial value (>HK $15/kg). Rockfish is regarded as of medium commercial value (HK$10–15/kg) (11).
Table 10.3 Top Five Adult Fish (by weight) Caught in Each AFCD Fishing Zone within the waters of the Study Area (1996 - 1997 Port Survey)
|
Code |
Fishing Area |
Top Five Fish Caught (by weight) |
|
|
|
|
Species |
Common Name |
|
0025 |
Ma Wan |
Siganus canaliculatus |
Rabbitfish |
|
|
|
Sebasticus
marmoratus |
Rockfish |
|
|
|
Mixed Species |
Mixed Species |
|
|
|
Argyrosomus
spp |
Croaker |
|
|
|
Sparidae
species |
Sea bream |
|
0034 |
Tsing Yi |
Mixed
Species |
Mixed Species |
|
|
|
Argyrosomus
spp |
Croaker |
|
|
|
Siganus canaliculatus |
Rockfish |
|
|
|
Acetes spp. |
Silver shrimp |
|
|
|
Muraenosox cinereus |
Conger pike
eel |
|
0035 |
Tsuen Wan |
Mixed
Species |
Mixed
Species |
|
|
|
Acetes spp. |
Silver
shrimp |
|
|
|
Muraenosox cinereus |
Conger pike
eel |
|
|
|
Argyrosomus
spp |
Croaker |
|
|
|
Siganus canaliculatus |
Rabbitfish |
|
0036 |
Tin Kau |
Mixed
Species |
Mixed
Species |
|
|
|
Acetes spp. |
Silver
shrimp |
|
|
|
Muraenosox cinereus |
Conger pike
eel |
|
|
|
Argyrosomus
spp |
Croaker |
|
|
|
Siganus canaliculatus |
Rabbitfish |
|
0037 |
Shum Tseng |
Mixed
crab species |
- |
|
|
|
Sillago
sihama |
Sand borer |
|
|
|
Siganus canaliculatus |
Rabbitfish |
|
|
|
Pseudosciaena crocea |
Yellow croaker |
|
|
|
Leiognathus brevirostris |
Pony fish |
The closest AFCD designated Fish Culture Zone
(FCZ) to the Study Area is located at Ma Wan which is approximately 4.4km away
from the Outfall O-1 at Yau Kom
Tau within the Study Area. As of 31 January 2001, updated information
from AFCD indicates that the Ma Wan FCZ consists of 132 licensed rafts with a
total licensed area of 14,557m2 (total gazetted area=46,300m2)
(12). The
main species cultured are the spotted grouper (Epinephelus chlorostigma), gold-lined seabream (Rhabdosargus sarba), mangrove snapper (Lutjanus argentimaculatus) and the pompano (Trachinotus blochii). There is no figure available for production
at this FCZ, although
The importance of the fisheries within the Study Area is addressed based on the baseline information provided above. The Fishing Zones within the Study Area are characterised as mainly of medium to low value. The catches from these zones were composed of juvenile mixed fish species, which are used as fish feed in mariculture. However, Ma Wan Fish Culture Zone was of high value in terms of fisheries.
The EIAO TM (Annex 9) states that spawning areas can be regarded as an important habitat type as they are critical to the regeneration and long-term survival of many organisms and their populations. Consequently, Ma Wan, which provides important fisheries habitat and potential fish fry spawning areas along the east Lantau coast, can be considered as important to fisheries (14).
Based on the preceding review of the available information on the capture and culture fisheries of the waters of the Study Area and its immediate vicinity, the sensitive receiver which may be affected by the proposed works associated with the Project has been identified as the Fish Culture Zone at Ma Wan (Figure 10.1).
As discussed in the Water Quality Impact Assessment Section 5, the construction works will involve site clearance, site preparation, earthworks, tunnelling by using tunnel boring machine, excavation of production shaft and other general construction activities etc. No dredging, reclamation or filling will be involved. Further to the water quality assessment in Section 5, no construction and operational impacts are expected to adversely influence the water quality and hence no unacceptable impacts on the fisheries resources within the Study Area will be expected.
From the information presented above, the fisheries impact associated with the Project is considered to be low. An evaluation of the impact in accordance with Annex 9 of the EIAO-TM is presented below.
· Nature of Impact: No severe, direct or indirect impacts will occur to fisheries resources within the Study Area as no unacceptable water quality impacts are expected further to the water quality assessment.
· Size of Affected Area: The construction of the Project will not result in the direct or temporary loss of fisheries habitats within the Study Area. Further to the water quality assessment, negligible impacts to fisheries will be expected due to the long distance of the Outfall O-1 from the major fishing areas and the small size of the construction works within the Study Area.
· Size of fisheries resources/production: Three fishing areas including the fish culture zone Ma Wan within the Study Area are of high to medium ranking for adult fish production in Hong Kong Waters, and another two fishing areas are of low commercial fisheries value. Due to the small size of the affected areas and the construction works restricted to coastal areas, the influence on fisheries resources/production should be negligible and acceptable.
· Destruction and disturbance of nursery and spawning grounds: Key fisheries resources consist of rocky substrate around Ma Wan, which provides important fisheries habitats. However, no destruction and disturbance of areas of fisheries importance is expected due to the project works.
· Impact on fishing activity: Based on the small size of the affected areas and because the construction works restricted to the foreshore at Yau Kom Tau, the impacts on fisheries resources are expected to be negligible.
· Impact on aquaculture activity: The Ma Wan FCZ is predicted not being impacted by perturbation of water quality from the construction works or operation of this Project.
In accordance with the guidelines in the EIAO-TM on fisheries impact assessment the general policy for mitigating impacts to fisheries, in order of priority are avoidance, minimization and compensation.
Impacts to fisheries resources and fishing operations have largely been avoided during the construction and operation of the drainage tunnel through the avoidance of dredging, reclamation and filling activities. Good construction practice and associated measures were recommended in Water Quality Assessment in Section 5 to control water quality impacts to within acceptable levels and are also expected to control impacts to fisheries resources. Hence, no fisheries-species mitigation measures are required during construction and operation of the drainage tunnel.
No adverse residual impact due to the construction and operation of the drainage tunnel is expected after the implementation of the proposed mitigation measures to control water quality impacts.
The implementation of the water quality mitigation measures stated in the Section 5 (Water Quality Impact Assessment) should be checked as part of the environmental monitoring and audit procedures during the construction period as presented in the separate Environmental Monitoring and Audit Manual. No other fisheries-specific measures are considered necessary.
Reviews of existing information on commercial
fisheries resources and fishing operations located within the Study Area have
been undertaken. Information from a
study on fishing operations in
The construction and operation of the Project will not give rise to impacts to fisheries, as there is no predicted adverse impact to water quality or habitat loss.
No special mitigation measures are required for fisheries resources, mitigation measures recommended to reduce impacts to water quality are also expected to mitigate any impacts to fisheries resources. The availability of literature on the fisheries resources of the Study Area comes mainly from the AFCD 1996-1997 (1).
(1) Agriculture, Fisheries and Conservation Department (1998) Port Survey 1996/1997.
(2) Agriculture, Fisheries and Conservation Department (2002a) Port Survey 2001/2002, web site www.afcd.gov.hk.
(3) Ibid.
(4) ERM (1998) Fisheries Resources and Fishing Operations in Hong Kong Waters, Final Report, for Agriculture, Fisheries and Conservation Department, March 1998.
(5) ERM (1998) Op cit.
(6) Agriculture, Fisheries and Conservation Department (2002b), web site www.afcd.gov.hk.
(7) ERM (1998) Op cit.
(8) Agriculture, Fisheries and Conservation Department (2002a) Op cit.
(9) Agriculture, Fisheries and Conservation Department (1998) Op cit.
(10)Agriculture, Fisheries and Conservation Department (1998) Port Survey 1996/1997.
(11)Fish Market Organization (2004), website: www.fmo.org.hk
(12)Scott Wilson (2001) Planning and Engineering Feasibility Study for Sham Tseng Development, EIA Final Report., for Civil Engineering Department.
(13)Op Cit.
(14)Op Cit.